🧭 Plot Summary
In Project 4-1-4 you watched a pendulum come back a little short every swing, and you saw that the missing energy had become thermal energy. Now you’ll turn that observation into a tool. If you know how much energy friction takes, you can budget the rest: how fast something will be going, how high it will climb, and how much of the energy you put in was actually useful.
On Day 1 you’ll measure how much work friction turns into heat, then practice the energy budget on sliding blocks, bouncing balls, and skidding cars. On Day 2 you’ll build a foam-tube valley, measure how much height a marble loses, and use that to predict the lowest release height that gets it over a hill. Then you’ll find out why no machine can be perfectly efficient.
What you will do in this activity
- Drag a block across different surfaces and measure how much work friction turns into thermal energy.
- Practice the energy budget equation on sliding blocks, bouncing balls, skidding cars, and skaters.
- Build a foam-tube valley and measure how much height a marble loses on each crossing.
- Use your own data to predict the lowest release height that gets the marble over a hill, then test it.
- Calculate the efficiency of machines and explain why none can reach 100%.
Why it matters
Every real machine, from a coaster to a car engine to an emergency slide, loses some energy to friction. Engineers don’t ignore that loss. They budget for it. That’s exactly what Project 4-2-3 asks you to do with a foam coaster.
✅ Self-Check Before You Roll On
Check off each item as you get there. These are not grades — they are your own signal.